Although often credited with prehistoric origin, most were erected in medieval times, and some in later centuries.[1] They are often situated close to a ford where carts could cross. According to the Dartmoor National Park, the word 'clapper' derives ultimately from an Anglo-Saxon word, cleaca, meaning 'bridging the stepping stones'[2] the Oxford English Dictionary gives the intermediate Medieval Latin form clapus, claperius, "of Gaulish origin", with an initial meaning of "a pile of stones".[note 1]

A fine example, the Postbridge Clapper Bridge (illustration, left), can be found at Postbridge, on Dartmoor. Its slabs are over four metres (13 ft) long, two metres (6 ft 6 in) wide and weigh over eight tons each, making the bridge passable to a small cart. It was first recorded in 1380 and was built to facilitate the transportation of Dartmoor tin by pack horses to the stannary town of Tavistock.

Some larger clapper bridges, such as at Dartmeet and Bellever, have collapsed – their slabs swept away by floods, or raided for building or wall construction. However, there are many other smaller examples in existence on Dartmoor and still in use, such as those at Teignhead Farm (close to Grey Wethers stone circles), Scorhill and across the Wallabrook stream.

While the term "clapper bridge" is typically associated with the United Kingdom, other "clapper-style" bridges exist throughout the world. One example is the Anping Bridge in China, which is over two kilometres long.